Late-onset hyporegenerative anemia in an infant with rhesus isoimmunization

Late-onset anemia is a complication of hemolytic disease of fetus and newborn. It includes late hemolytic anemia and late hyporegenerative anemia. This case report is to discuss an Rh isoimmunized infant who presented with late-onset hyporegenerative anemia. The infant had low reticulocyte count, negative direct antiglobulin test, high erythropoietin, and high ferritin levels. She was treated with repeated blood transfusions and improved after 4 months of age. The follow-up of infants with Rh isoimmune hemolytic disease is needed for identification of late-onset anemia.